[en] We developed a new system to estimate liver volume using CT-scan images printed on the films. This device is composed of X-Plan 360i and personal computer. In 35 patients with hepatocellular carcinoma, liver volume was estimated before and 4 to 6 weeks after hepatic resection. The presumed liver volumes calculated preoperatively were significantly correlated with the weight of the resected specimen. The postoperative increasing rates of residual liver volume was regulated by resected liver volume ratio and severity of associated cirrhosis. Four cases which suffered from postoperative liver insufficiency showed the lower postoperative rates than the patients without liver insufficiency. Measurement of liver volume with this method is simple and promises to play an important role for evaluating hepatic reserve. (author)